Pairat Songpanich และ Vipa Hongtrakul. (2009) Nymphaea 'Siam Blue Hardy': The World's First Blue Hardy Waterlily. <i>Thai Agricultural Research Journal</i>, <i>27</i>(1), 68-81.Pairat Songpanich และ Vipa Hongtrakul. "Nymphaea 'Siam Blue Hardy': The World's First Blue Hardy Waterlily". Thai Agricultural Research Journal 27 (2009):68-81.Pairat Songpanich และ Vipa Hongtrakul. Nymphaea 'Siam Blue Hardy': The World's First Blue Hardy Waterlily. Department of Agriculture:ม.ป.ท. 2009.